Knewton Challenge: Win Knewton Shirt and GMAT Club Tests

!	The thread is closed for submissions. The winner will be announced on Tuesday.

Hey everyone! Hope you enjoyed your long weekend, and thank you for all of your thoughtful responses! It was difficult choosing a winner, but we decided that the submission that most clearly and comprehensively explained the correct answer belonged to:

Mourinhogmat1!

Answer: E

Here's how he got it:

Evidence 1: For a new Kangaroo gestation period = 39days (SHORT GESTATION)
Evidence 2: Hind limbs are not well developed but Fore limbs are well developed. Why?
Evidence 3: So, that they can climb in to the pouch (Key word is So, that)
Main Conclusion: The evidence found in the lions strengthens the conclusion that developed forelimbs meant that they used this for climbing into the pouch of the adult lion.

Assumption should Eliminate a possibility of use of the fore limb or suggest some similiarity between Lions and Kangaroos.

A) INCORRECT. A addresses an assumption for Evidence 1, which is in fact irrelevant to the argument
B) INCORRECT. This highlights a relative comparison between the two limbs which is outside the scope of this argument.
C) INCORRECT. Outside the scope of this argument as well. Because it refers to a hypothetical possibility not relating to the evidence or the conclusion.
D) INCORRECT. This is the correct "wrong" answer. In fact this question talks about the possibility of not only this hind limbs. This statement talks about Fore limbs being the ONLY reason for the climbing. In fact this aspect of the argument is not discussed here. We only wish to know if the presence of a fore limb strengthens the fact that fore limbs are present for climbing into the pouch.
E) CORRECT. Try the negative test to confirm the answer: Newborn marsupial lions would not have had only their forelimbs developed if this development were used by the marsupial lions. This is also the only answer which connects the new born marsupials to the EVIDENCE OF ANCIENT MARSUPIALS (which maybe adults or young ones).

Fantastic job, mourinhogmat1!

A few Knewton pointers to clarify for those who were stumped by this question:

- When approaching critical reasoning problems, it's always a good idea to look at the question before the prompt. That way, you know what you're looking for when you're reading.

- In this question, we're looking for an assumption - the necessary bridge that leads from the evidence to the conclusion. As mourinhogmat1 did, the best way to approach this problem is to break down every piece of the prompt in order to figure out what is evidence, what is the author's conclusion, and what the unstated assumption is that links them.

- As mourinhogmat1 correctly determined, the first two sentences, as well as the first part of the third sentence, are evidence. The author's conclusion, therefore, is: (like kangaroos,) newborn marsupial lions must have needed to climb into their mothers' pouches.

- Thus, we have to look for the assumption that draws a connection between kangaroos and marsupial lions, or illustrates NEED. Let's look at each choice and see how well it fits this criteria:

A: The first thing that should strike you about this answer is the word "all." We're not concerned with all animals, we're only looking for a connection between kangaroos and marsupial lions. INCORRECT

B: This answer choice draws a false comparison. We're not concerned with how advantageous the forelimbs were, we just need to know if they were necessary. INCORRECT

C: The blurb doesn't mention paleontologists anywhere - this answer choice does not address the conclusion we're trying to support. Even if paleontologists were able to find evidence of it, this choice doesn't indicate the necessity of it. INCORRECT

D: This seems like the correct answer, and many students incorrectly fall for this option. The problem here is the misleading wording. Whether they COULD have climbed into their mothers' pouches doesn't support the conclusion that they NEEDED to. INCORRECT

E. This answer choice is tricky because of the confusing double negative wording. It's best to rephrase it, so that the meaning is more clear: "would not have developed if they were of no use" = "developed because they were of use" - this indicates development for a specific purpose, which supports the conclusion that marsupial lions NEEDED to develop forelimbs. CORRECT

Congratulations again to mourinhogmat1, look out for a private message with details on collecting your prize!

For everyone else, thank you again for your submissions! Did you guys enjoy this challenge competition? We'd love to hear some feedback on if you'd like us to continue/formatting improvements/anything else.

Thanks again, looking forward to your thoughts!

Jessie
Knewton GMAT Team

Congratulations mourinhogmat1!!!
I liked the clue for what to look “Assumption should be…”, also the “correct wrong answer” concept/idea is highlighted, and finally the negation test (I wish it was used on D as well and I wish there was better formatting).

Also, I would like to thank all members who responded and would like to identify these members who got very close to winning:

gmatcracker24 – interesting approach; concise
Dhaswe – very direct and good explanation but a bit minimalistic
yogesh1984 – chose D but gave great reasoning
vamshikrishna – first post on GMAT Club and very clear logic but did not fully list why D was wrong (found only one of the reasons, though was enough to get to the correct answer)
a1choi – very good overview
karan2483 – great answer but the explanation of why D is wrong could be stronger
bficcade – also a first time poster. Did not address other answer choices except the correct one
abidshariff – Kudos for the multi-color use. Wish spent more time explaining the premise/conclusion/assumptions in the passage (what these concepts are)
alicegmat – Fantastic answer and was definitely one of the leading choices but it did not offer a glance at a “raw assumption” that one would come up with after reading the question. The strategy to answer the question in your own words without looking at the answer choices is not reflected here.

Hello bb,



Point well taken! Thank you for pointing out a better approach to me! I had actually thought of an assumption ahead of time, and my linking bridge between premises and conclusion was that: Ancient marsupial lions would not have only well developed limbs, had they don't needed them to climb to mother's pouch.

As this was absent in the choices, I went for general use, as even without this, the conclusion would die!

My bridge for the gap was



Thank you.